The invention relates to a process for producing a fine pored silicone foam by free foaming the two-component foam reaction mixture in which the reaction component A, a silicone composition, contains a silicone polymer having at least two double bonds per molecule, preferably vinyl groups, an organo-platinum catalyst, fumed silica, water, and if appropriate, further additives (alone or in combination) such as color pigments, foam regulators flame retardants, fillers and the like. The crosslinking component B is polydimethyl hydrogen siloxane. Compared to other known foams, such as polyurethane foam, PVC foam, or chloroprene foam, silicone foams exhibits a number of favorable properties which make a wide application range of these foams possible. These properties include above all: UV resistance, resistance to salt water, physiological harmlessness, odor free, high comfort of wear, when used as or in items of clothing chemical resistance, resistance to aging, tightness with respect to fluids, breathability or gas permeability, low combustibility and low foam density.
EP 0 416 229 A2 discloses a process for producing a fine pored, soft-elastic, sealing foam for lid, casing and cavity seals, in which the reaction components of the foam are processed in a low pressure, two-component meter mixing machine and made to foam in a free rise process without the addition of heat. One reaction component contains a silicone polymer having at least two double bonds in the molecules, preferably vinyl groups, and an organo-platinum catalyst, as well as further additives, if appropriate, The other component is formed from hydrogen siloxane as the crosslinking agent. A small amount of water being added to component A as an additional crosslinking agents and as a blowing agent. The addition of water causes the hydrogen siloxane to react almost completely during the foaming of the silicone composition so that a highly hydrogen blowing effect is obtained. A post reaction, having detrimental effects on the quality of the silicone foam is avoided.